Filing stations for dispensing gasoline and other fuels have long had a problem with vehicles pulling away from the fuel dispensing pump with the dispensing nozzle still inserted in the vehicle's tank, or with the nozzle or dispensing hose otherwise secured or hung on the vehicle. Such incidences usually result in damage to the dispensing pump and/or breakage of the dispensing hose. It will be appreciated that repairing the resulting damage to the dispensing pump and hose can be extremely costly. Further, the fuel spillage which can result from such damage can create a dangerous and possibly life threatening condition. Attempts have been made to overcome this problem by installing two hoses joined by a breakaway coupling device on the dispensing
pump, with the coupling device being designed to disengage and seal the hose ends when pressure is exerted on the coupling as in the case where a vehicle pulls away from the pump with the nozzle or hose attached. Many of these device comprise two fluid communicating housings secured to the hose end and which are secured together in fluid communication with shear pins which are designed to shear and disengage the housings in response to force in excess of a preselected value being applied to the coupling. For example, such a device is disclosed in U.S. Pat. No. 4,896,688. Other breakaway coupling devices are disclosed in
U.S. Pat. Nos. 4,674,525; 4,646,773; 3,741,521; and 3,719,194. Whereas such devices have proven successful in obviating damage to the operatively associated dispensing pumps and hoses, each time the coupling disengages in response to excessive force being applied, new shear pins must be installed in order to place the coupling back in service. Because of the inconvenience and maintenance costs associated with couplings which rely upon shear pins, much effort has been put into designing couplings which include disconnect mechanisms which allow the coupling to be recoupled without the replacement or repair of components. For example, U.S. Pat. No. 4,691,941, discloses such a coupling. However, such coupling devices tend to be complex and costly.
Therefore, it is an object of the present invention to provide a breakaway hose coupling device for releasably joining two dispensing devices and for selectively disengaging and terminate the flow of fluid from the dispensing devices in response to a disengaging force in excess of a preselected value being exerted on the device.
It is another object of the present invention to provide a breakaway coupling device which utilizes shear pins to effect the automatic disengaging of the coupling, while obviating the need to replace shear pins each time the coupling disengages.
Yet another object of the present invention is to provide a breakaway coupling device which is inexpensive to manufacture and maintain.